3 Suggested Answers

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.Goodluck!

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires (as mrgreenz suggests); the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.
Hope this is helpful as well.

Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.

Related Questions:

code p 1399 refers to random misfire ===causes --fuel /ignition--MAP sensor---IAC valve ( idle air control valve )
misfires are more from faulty injectors and low fuel pressure than from electronic problems
unless you have been burning lots of oil , the ports will be clean so have the injectors serviced

p1399 is a random misfire code and honda has reported for various models
that this could be caused by clogged egr ports, in addition there is
the possibility that the valve clearance spec may be out of range.check plugs and wires first and proper gap.

Honda does not supply a diagnostic flow chart for this code. P1399 is a random misfire code and Honda/Acura has reported for various models that this could be caused by clogged EGR ports. In addition there is the possibility that the valve cleareance specification may be out of range

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires; the EGR valve to make sure it doesn't leak; your
fuel pressure which can cause random misfires if the pressure is too
low; and injectors if they are really dirty. If you have really high
mileage, I probably would first just change out the plug wires with a
new set, then reset the DTC and see if the code comes back.

If only one of your cylinders was misfiring, you probably would be getting a more specific code than P1399.
Also check the distributor rotor along with the cap and coils and wires (as mrgreenz suggests); the EGR valve to make sure it doesn't leak; your fuel pressure which can cause random misfires if the pressure is too low; and injectors if they are really dirty. If you have really high mileage, I probably would first just change out the plug wires with a new set, then reset the DTC and see if the code comes back.
Hope this is helpful as well.

Get your self a EGR valve it is sticking or the EGR port is blocked i
can tell you how to test it you have a volt meter but i am 100% THAT
WHAT IT IS
Code P1399 is a pending misfire code.
HOW TO TEST

1. Check EGR position sensor voltage on the White/Black wire at
idle - look for 1.1 - 1.2 volts with the EGR valve closed. If the EGR
position sensor voltage is higher than 1.2 volts, the EGR valve is
stuck open.

2. Can unplug the EGR valve and apply power to the terminal on the EGR
valve that the Pink wire would normally go to and ground the terminal
on the EGR valve that the Black wire would normally go to and see if
the engine stalls at warm idle.